CVE-2026-64502

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices<br /> <br /> ad_sigma_delta_clear_pending_event() falls through to the status register<br /> read path for devices with has_registers = false and no rdy_gpiod. For<br /> such devices, ad_sd_read_reg() skips the address byte entirely and clocks<br /> raw MISO bytes with no address phase — making it byte-for-byte identical<br /> to reading conversion data. If a pending conversion result is present,<br /> this partially consumes it and corrupts the data stream for the subsequent<br /> ad_sd_read_reg() call in ad_sigma_delta_single_conversion().<br /> <br /> Furthermore, with num_resetclks = 0 on these devices, data_read_len<br /> evaluates to 0. If the clocked byte has bit 7 clear, pending_event is set<br /> and the code attempts memset(data + 2, 0xff, 0 - 1), overflowing to<br /> SIZE_MAX and corrupting the heap.<br /> <br /> Fix by returning 0 immediately when neither rdy_gpiod nor has_registers<br /> is set. This is safe for all current registerless devices: ad7191 and<br /> ad7780 (with powerdown GPIO) are reset between conversions by CS<br /> deassertion, so there is no stale result to drain; ad7780 (without<br /> powerdown GPIO) and max11205 are continuously-converting and cycle ~DRDY<br /> at the output data rate regardless of whether the previous result was<br /> read, so the next falling edge fires naturally.<br /> <br /> A future registerless device that holds ~DRDY asserted until data is read<br /> would be broken by this early return and would require either<br /> num_resetclks set or a rdy-gpio.<br /> <br /> The same heap corruption is reachable on any device with rdy_gpiod set<br /> but num_resetclks = 0: if the GPIO indicates a pending event, the drain<br /> path executes memset(data + 2, 0xff, 0 - 1) regardless of has_registers.<br /> Add an explicit data_read_len == 0 guard after the pending event check;<br /> the stale result is then consumed by the first ad_sd_read_reg() call in<br /> ad_sigma_delta_single_conversion().